Dumping mechanism



DecQ 25, 1951 Filed Dem 12, 1949 H. C. SMITH ETI' AL DUMPING MECHANISM :s 'sheets-'sheep l Dec. 257 1951 H. c. SMITH ETAL 2,579,708

DUMPING MECHANISM Filed nec. 12, 1949 s sheets-sheet 2 Dec. 25, 1951 H. C. SMITH mL 2,579,708

DUMPING MECHANISM Filed Dec. 12, 1949 's sheets-sheet 5 Il 40 In# H Ill j f 54 38 n I l l" f l' 7 92 4/ 945 44 46 56 we* www Patented Dec. 25, 1951 DUMPIN G MECHAN ISM Haywood C. Smith and James C. Petrea, Durham, N. C., assignors to Wright Machinery Company, Durham, N. C., a corporation of North Carolina Application December 12, 1949, Serial No. 132,442

12 Claims.

This invention relates to weighing machines and particularly to a dumping mechanism arranged to eiiect tilting of a material receiving and weighing member to effect discharge of the weighed material therefrom.

In a preferred embodiment oi the present invention a weighing mechanism comprises a tank containing a fluid in which a iioat is buoyantly supported. A supporting member connected to the float is arranged to releasably support a material weighing bucket whereby the float moves to a lower position in the supporting fluid upon depositing of suicient material in the bucket. When a predetermined weight of material is deposited, the oat reaches a predetermined level and causes actuation of of a mechanism to dump the material from the bucket. It is this dumping mechanism that constitutes the subject matter of the present invention and is characterized by a structure pivotally supported on a frame member adjacent the bucket. The structure has means for engaging a portion of the bucket and an element pivoted thereon which is provided with means for engaging another portion of the bucket. When the element is pivoted on the structure in a predetermined manner, the bucket is gripped and held by the dumping mechanism and lifted free of support by the float and then dumped by a pivotal movement of the mechanism.

A cam-actuatedlink drives the pivoted element only to effect all of the movements described, in a single cycle of operation. Itis also contemplated that the invention include a dumping mechanism wherein all of the elements are not pivoted relative to each other and the frame but wherein some of said elements may be slidably mounted relative to others.

It is, therefore, an object of this invention to provide a weighing machine wherein a weighing bucket is supported by weight responsive means free of engagement by any other mechanism during the weighing cycle and wherein dumping means engage and lift the bucket from the weight responsive means during a dumping cycle.

It is a further object of this invention to pro vide, in a weighing machine, novel mechanism to lift and dump a material weighing bucket.

It is still another object of this invention to provide a. weighing machine as set forth above wherein the weighing cycle is accomplished free of engagement with any dumping mechanism.

It is a still further object of this invention to provide a weighing machine oi' generally imw proved construction and operation involving s imple mechanisms economical to produce.

Another object of the invention is to provide an improved dumping mechanism for a weighing machine.

Other objects and advantages of the invention will become apparent to those skilled in the art as the description proceeds in connection with the accompanying drawings wherein:

Fig. l is a side elevational view of a portion of a weighing machine embodying the present invention with certain parts omitted for clarity of illustration and other parts being broken away.

Fig. 2 is a sectional view, on a somewhat larger scale, taken substantially on the line 2 2 of Fig. l and looking in the direction of the arrows.

Fig. 3 is a sectional view of a portion of the device taken substantially on the line 3--3 of Fig. 2 when looking in the direction of the arrows.

Fig. 4 is a top plan view of that portion of the mechanism shown in Fig. 3 and Fig. 5 is a side elevational View similar to that of Fig. l but showing the parts in different relative positions.

The weighing machine in which the present invention is incorporated includes a frame plate i0 having a pair of upstanding frame members I2 iiXed thereon. A hollow tank l'fl is xedly supported on the machine and is Vconstructed to be fluid-tight to retain a suitable fluid therein. A oat (not shown) is buoyantly supported in the fluid within the tank I4 and is connected to an upstanding member I6 carrying at its upper end a bucket-supporting yoke comprising a cross member I8 and upwardly extending elements 20 attached to the ends of the cross member I3, as shown in Fig. 2. Each of the members 2U is provided with an upwardly open V-shaped seat 22 at its upper end and the seats 22 on the two members 20 are at substantially the same elevation. Suitable guide means (not shown) hold the member I6 in upright position during its vertical weighing movements. The weighing bucket 24 is of such dimensions that it is readily received between the upstanding members 20 and is provided at each end with an outwardly extending trunnion or pin 26 receivable in the adjacent seat 22. The trunnions or pins 2t are positioned somewhat forwardly (to the left as seen in Fig. l) of the center of gravity of the bucket 24 so that the empty bucket normally tends to swing clockwise as seen in Fig. 1. A bracket 28 is fixed to the member l5 and extends rearwardly thereof, terminating in a pad 30 in position to engage the bottom of the bucket 24 to normally hold the bucket in an upright material receiving position.

55 It is to be understood that the term bucket as .ing mechanisms.

Veachlframe member i2 is identical to that on the 'other frame member, but arranged in reverse rerestraining it against axial movement.

an interruption in the feed .of Imaterialto the bucket and to actuate a cam shaft 32 to effect a cycle oi' operations. including dumping of material from the bucket 24.

Pivoted to each upstanding frame member I2 is an L-shaped member 34 and associated dump- The dumpingA mechanism on lationand only one will be described in detail.

The L-shaped member 34 is pivoted to the frame member i2'by a pivot'BB permitting the member 34 to -pivot freelyon a horizontal axis but The. L- shaped .member 34 includes an upwardly extend- Y ing portion 3B directed upwardly from the pivot 36 and Ya laterally extending portion 4e'extending substantially.horizontally, in the normal. po-

sition .of .the member 34', from the pivot 36. A block42 Iisrigidly attached to the upwardly extending portion 38 on the inner side thereof between the portion 38 'and the adjacent end of 4thebucket 24... The block 42,'is4 provided with a portion 52V positioned in an opening'54l in the a lever 48. A suitable set screwor `the like 56 threadedinto the 1ever..48"engages thereduced end portion"52 to hold the 'lever'48 fixed to the ,pivot 5G. A head 58 on the pivot 5H engages the outermost face of the member 34 toprevent axial y,

movement of the pivot 5(1.and'the leverefl'relative to the L-shaped'member: Asshown, the lever 431s pivoted to the member VV34 onV the same side thereof as the Vblock 42. Thelever`48, however, is somewhat thinner; when measured in a direction parallel to the axis'of pivotsV 3S and 50, than the corresponding" dimensionI ofthe block 42. As clearly shown lin* Fig. 3; the lever 48 is of generally T shape andanupwardly` extending V.ear thereof isprovided with 4the openingl1 referred to. The other 'earof thelever 4s ex- Y Vtends downwardlyandis pivoted', adjacent its lowermost end, to an actuating link BD. The actuating link 60 is provided with a spherical seat engaging a'spherical bearing portion '62 mounted on a pivot pin.64 passingv therethrough and through the lever 48. A pair cf lock nuts- @Gare provided to .hold .the partsin the described assembled relationship;

The stemof the T-shaped lever 48 "extends generally horizontally toward the pivot 3E and to a position below the trunnion 2li on the bucket 24. Directly below the trunnion 2% the lever 43 is provided with an upwardly facing open seat d8 and in the position shown in Fig. 3 the seat 63 is opposed to and directly below the seat i4 in block 42. The stem portion of the lever 4S extends alongside, but clear of, the upwardly extending member 26 which supports the trunnion 23 during weighing movements.

Each of the levers 48 is provided with an actuating link 58 pivoted thereto at one end and pivotedat its opposite end to one of a pair of arms lil; only one of which is shown, iixed to a rock shaft 'l2 journalled in brackets 'I4 carried by the frame plate Iii. The cam shaft 32, previously referred to,y is also journalled in the brackets i4 and has iixed thereon a cam it having a closed cam trackA 58 in one face thereof. A cam follower extends into the cam track i3 andis lcarried by one end of a cam lever 32, also xed'to the rock shaft l2. rThe cam follower Sil is preferably in the form of a laterally extending roller journalle. on the free end ofv the lever 82. It will beapparent that arotation ci' the camshaft 32 andthe cam 'i3 will cause a cycle of rocking movement of the shaft 'l2 and a cycle of reciprocation of the links Sil. Each 0i' the links EG may comprise a plurality of parts threadedly engaged with each other to vary, the eiective length of the links, all in avveil-kncwn manner and as clearly shown in Figs. l and 5 of 'the drawings wherein a central: portion 6I is shown threaded at its ends into end members 63. Lock nuts e5 retain the parts against accidental displacement.

Referring new to Figs; 3 and 4, the upwardly extending frame members l2 are provided, adjacent the top endsl thereof, with angle brackets 84 xed thereto and having flange portions ES extending Vinwardly toward the bucket 24 and across the path of movement of 'the'L-shaped member 34. Each of the anges it is provided with a buffer or pad 87 to be engaged by one edge of the upwardly extending portion 380i the member 34 when that `portion is in an upright position as indicated in Fig. 3.' The brackets 84 and pads Bl thus constitute stop means limiting pivotal movement of the members 34 in one direction about their pivots 3B. A tension spring 88 is iixed at one end, by means of an eyelet 90, tothe free end of the stem'of the T-shaped lever 48 and engages, at its other end, an eyelet 92 iixed to the block 42 on the member 34. Asis 'evident from Fig. 2, the spring 38 extends Iupwardly along a path between the innermost edge of the flange 85 of bracket 84 and the outermost end of the bucket 24 whereby the assembly comprising member 34 and lever 48'may pivot about the axis of 3S without interference between the spring 88 and the bracket 84.

The bucket 24 carries secondtrunnions 94 at each'end thereof vertically spaced thesame fixed distance above the previously described trunnions 26. The trunnions 94 extend outwardly'of the bucket 24 past the innermost edge'of the block 42 to lie in opposed relation to and below the seats 44 but between the side walls 45.

The cam 'I6 having the closed cam track i8 is, in an obvious manner, eiective to positively position the levers 48 in predetermined position (that shown in Fig. 3) in the normal or stopped position of the-cam 15. Under such conditions the pivots 64, between the links 53 and the levers 48, may be considered as being temporarily fixed s to the frame of the machine, which is the normal position referred to and is the position of the parts during a weighing cycle. Considering the pivot 64 so fixed it will be clear that the spring 88, acting along a line on the same side of the axis of 36 as the stop 81, will urge the member 34 to turn counter-clockwise about its pivot 36 (as seen in Fig. 3) and against the stop member 8l. The parts will thus normally be held fixed in the position shown in Fig. 3 with the seats 44 and 68 a fixed distance apart, in vertical alignment with each other, and in vertical alignment with the trunnions 26 and 94.

At the commencement of a weighing cycle, the float, previously referred to, is held by stop means (not shown) to a position just slightly above that it assumes under the inuence of a predetermined weight of material in the bucket 24. Thus the weighing mechanism is preloaded and downward movement of the bucket and float does not 'take place until the weight of material in the bucket is nearlyequal to the predetermined desired weight. After that weight of material has been accumulated in the bucket 24 and downward movement begins, the trunnions 94 and 25 may move downwardly, as seen in Fig. 3, a substantial distance without engaging the trunnion 26 with seat 68. At the lowermost position of the bucket and float, the trunnion 26 is still a short distance above the seat 68 in lever 48 and in this position control means, referred to previously but not shown, initiate operation of mechanism to cause a single revolution of the cam shaft 32. As the cam shaft 32 rotates the cam track 'I3 will cause the link 66 to oscillate from the posiment of the link 50 to the left will cause the lever 4B to swing about the pivot 52 in a clockwise direction. The L-shaped member 34 is heid against the stop 81 by spring 88, thus maintaining the pivot 52 in xed position during the initial part of the dumping cycle. Clockwise rotation of the lever 48 results in first lifting the seat 68 thereon into engagement with the trunnion 26 and further movement lifts the trunnion 26, the bucket 24 and the trunnion 94 upwardly. The yoke 2B follows the upward movement of the trunnion 26 for a short distance until the stop means previously1 referred to become effective to limit upward movement of the `float. Upward movement of the yoke 2D is stopped by said stop means before the trunnion 94 has moved upwardly far enough to engage the seat 44. Thus the trunnion 26 is lifted completely free 'of the yoke 20 and the bucket and its contents are supported entirely by the lever 43. The spring 38 is provided with suihcient initial tension to remain under substantial tension at all times, even when the lever 48 has been swung clockwise sufficiently to engage the trunnion 94 in the seat 44. Thus the member 34 is maintained in contact with the stop 81 until that time. The trunnions 26 and 94 are both rigidly carried by the bucket 24 a fixed distance apart so it will be obvious that upon engagement of the trunnion 94 with the seat 44, further clockwise movement of the lever 48 about the pivot 52 is prevented. At this time the link 60 is continuing its movement to the left and since the lever 48 cannot pivot on 52, the entire structure, lever 48, member 34, and the bucket 24, will be swung as a unit about the axis of the pivot 36 in a clockwise direction as seen in Fig. 3 to the position shown in Fig. 5, which is the dumping position of the bucket. Suitable receiving means not shown, are provided to receive the material thus dumped from the bucket. The position in Fig. 5 is attained after one-half revolution of the cam shaft 32. The other half of the single revolution of the shaft 32 merely returns the parts to the position of Figs. 1 and 3, reversing the sequence of movements just described.

As previously described, the stem I6 has 'a bracket 28 and pad 3U thereon to normally hold the bucket 24 in upright position. When the weight of the bucket is supported entirely by the trunnion 26 resting on the seat 68 of lever 48, and the bucket is lifted free of the yoke 20, the pad 3B will obviously be no longer effective to insure maintenance of the bucket in upright position. It is quite likely that the bucket would then be unbalanced, due to the indeterminate position of the material therein, and would tend to tilt as it is lifted free of the yoke 20. To prevent such tilting, or at least limit the tilting to a small amount, the seat 44 is provided with downwardly extending side wall portions 46, previously described. In all vertical positions of the bucket 24, the trunnion 94 is within the space between the side walls 46 but is free to move vertically therebetween without interference and to be guided into the apex of the seat 44, as described.

It is not necessary, for proper operation of the dumping mechanism, that the trunnion 26 be lifted clear of the yoke 20. The parts can be so dimensioned and related that the axis of the trunnion 26 coincides with the axis of the pivot 36 when the trunnion 94 engages the seat 44. With such an arrangement the yoke 20 could be permitted to follow the trunnion 26 upwardly and during the actual dumping movement the trunnion 26 would merely rotate on its axis. There would be no lateral movement of the trunnion 2S and no tendency for it to laterally displace itself from the seat 22 on yoke 20.

Although a single preferred embodiment of the invention is shown and described herein, it is to be understood that further modifications may be resorted to without departing from the scope of the invention as defined by the appended claims.

We claim:

1. In a weighing machine, receiving means to receive material to be weighed, means supporting said receiving means for balancing movement un der the influence of material therein and for pivotal dumping movement relative thereto about a substantially horizontal axis, means normally free of engagement with said receiving means during said movement, said last-named means being movable into position to engage said receiving means and being further movable to impart a dumping movement thereto about said substantially horizontal axis.

2. In a weighing machine, a bucket to receive material to be weighed, movable means supporting said bucket for movement therewith to a predetermined position, dumping means normally out of engagement with said bucket during movement thereof to said position, said dumping means being movable into supporting engagement with said bucket and further movable to tilt said apropos bucket about.` an axis? passingl therethrough while said bucket k-is supported thereby.

'support .elementsand dump the contentsv thereof 1 whilefsaid bucket is free of said supporting means.

4; Ina weighing machine, a bucket to receive materialto; be weighed, movable means sup- -porting-saidfbucket for vertical weighing movement between predetermined positions, said suplzrortng'rneansv having' aniupwardly open seat, a rstftrunnion on said bucket engageable on said seat forsuppor-ting said bucket thereon, a second trunnion on said bucket-spacedy from said first trunnion; a dumping mechanism having relatively movableY elements normally free of engagement with said. trunnions during said weighing ,movementv said-elements being relatively mov- A able,.when said 4bucket is in its lowermost position,` to engage said trunnions, respectively, and therebygripand lift said bucket from said seat, saidelements being further movable, as a unit, while gripping said trunnions therebetween, to tilt saidbucket and dump the contents there- ',frorn.

5. In a weighing machine, a frame, a bucket to receive material to be weighed, means vertically 'movable on said frame and having an open seat thereon, a rst `portion of said bucket removably engageable in said seat for supporting said bucket thereon for vertical weighing movement therewith between an upper and al lower position, a

sec'ond'portion oi' said bucket spaced from said iirst portion, a rst member movably mounted ontsaid frame and 'having a portion defining an open-seat `adjacent Asaid second portion of said bucket, a second member movable relative to said `frame and'having an open seat adjacent a portion Vof saidfi'rst portion of said bucket, said second member. being movable to engage its seat "withfsaid*nrstwportion of said bucket YVand lift saidbucket'iree'o said supporting means and to seat said second portion of said bucket in said open seat of said rst member to thereby grip Y said bucket between said members, said members being further pivotally movable as a unit about a'comrnon axis on said frame, to dump the contents from said bucket.

6-.-In a weighing machine, a frame, a bucket to. receive material to be weighed, means vertically movableon said frame and having an upwardly openseat thereon, a first trunnion on said bucket. removably engageable in said seat for supporting said vbucket thereon for vertical weighing movement therewith between an upper andV a lowerposition, aseoond trunnion on said .bucket spaced above-said iirst trunnion, a rst member movably mounted on said frame and i having a portion presenting a downwardly facing vseatabove saidsecond trunnion, a second .member movablymounted on said Virst member and havingan upwardly facing seat spaced below aportion ofY said rst trunnion, said second memvber vbeing Vmovable.upwardly to engage said iirst trunnion and lift said bucket free of said supporting means and to seat said second trunnion in said downwardly acingseat to thereby grip said bucket between said members, said members thereafter being movable as a unit on said irame, to dump the contents from said bucket.

7. In a weighing machine, a frame, a bucket to receive material to be weighed, means vertically movable on said frame and having an upwardly open seat thereon, a rst trunnion on said bucket removably engageable in said seat for supporting said bucket thereon for vertical weighing movement therewith between an upper and a lower position, a second trunnion on said bucket spaced above said rst trunnion, a iirst member pivoted to said frame and having a portion presenting a downwardly facing seat above said second trunnion, a second member pivoted to said first member on an axis horizontally spaced from the pivot axis of said rst member and from said first trunnion, said second member including a portion defining an upwardly facing seat lbelow said first trunnion, means normally holding said members in a predetermined relative position wherein said bucket is free to move vertically between said positions without engaging said trunnions on said seats, said holding means being operable to swing said second member about its pivot aXis to engage its seat with said first trunnion and to then lift said trunnion bucket free of said supporting means and engage said second trunnion with said seat on said iirst member whereby to grip and support said bucket between said members for pivotal dumping movement about the pivot axis of said iirst member.

8. A weighing machine as donned in claim '7, including stop means on said frame to limit pivotal movement of said nrst member in one direction, and resilient means urging said rst member against said stop means.

9. A weighing machine as defined in claim -7 including stop means on said frame to limit pivv otal movement of said rst member in one direction, a tension spring connecting said rst and second members and arranged to urge the second member to pivot on the first member to bring the seats thereon toward each other, and operating means including a reciprocable link pivoted to said second member to pivot said members as a unit to dump said bucket when reciprocated in one direction and, to return said bucket to upright position with said rst member against said stop means and to further swing said second member on said first member to separate said seats and lower the said bucketonto said supporting means when reciprocated in the other direction.

l0. A device as set forth in claim 9, including a closed cyclically operable cam arranged to reciprocate said link,

il.,l In a weighing machine, a frame, a member .pivoted to said frame on a substantially horizontal iirst axis and having portions extending upwardly and laterally from said airis, stop means on said frame engaging said upwardly extending portion on the side thereof opposite said laterally extending' portion, a lever pivoted to the said laterally extending portion of said member on -a second` axis substantially parallel to said iirst axis, said lever extending toward said first axis, said upwardly extending portion having a downwardly facing irst seat thereon-and said lever having an upwardly facing seat thereon below vun 9 and opposed to said rst seat, control means connected to said lever eccentric to both said axes and cyclically movable in a plane normal to said axes, resilient means urging said lever to swing on said member to cause said seats to `approach each other and to urge said member against said stop means, weight sensitive means vertically movable on said frame between upper and lower positions, a Weighing bucket supported by said Weight sensitive means, portions of said bucket extending between said seats for vertical weighing movement therebetween, said control means normally holding said seats spaced apart a distance such that said portions of said bucket do not engage said seats at either of said upper or lower positions, but being operable to move said seats toward each other and grip said portions of said bucket therebetween.

10 12. A weighing machine as defined in claim l1, wherein said resilient means comprises a tension spring connecting said lever and said upwardly extending portion, said spring acting on a line passing to one side of said first axis and on the same side thereof as said stop means.

HAYWOOD C. SMITH. JAMES C. PETREA.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,149,079 Popow Aug. 3, 1915 Lul. 

